1. Field of the Invention
This invention pertains to rotary vibrations induced by a pneumatically-actuated roller within a housing. This roller is revolved so that heavy-duty vibrations are produced with a reduction of noise levels of less than those found in conventional devices.
2. Description of the Prior Art
Rotary vibrators, and particularly those actuated and/or driven by pneumatic forces, are well known. Rotary vibrators have been used for many years and many include concrete compacting devices such as those to FONTAINE, as exemplified in U.S. Pat. No. 2,763,472, as issued Sept. 18, 1956; U.S. Pat. No. 2,967,048, as issued Jan. 3, 1961; U.S. Pat. No. 3,030,079, as issued Apr. 17, 1962; U.S. Pat. No. 3,162,426, as issued Dec. 22, 1964, and U.S. Pat. No. 3,376,021, as issued Apr. 2, 1968. Also known is United Kingdom Pat. No. 2,010,402, of June 27, 1979, to ESEF HALILOVIC. This same inventor has a U.S. Pat. No. 4,300,843, as issued Nov. 17, 1981. Other U.S. patents of note are U.S. Pat. No. 2,834,584 to BONDESON et al, as issued May 13, 1958; and to BONDESON independently in U.S. Pat. No. 2,956,788, as issued Oct. 18, 1960. Of note is BODINE JR., U.S. Pat. No. 3,191,911, as issued June 29, 1965; BEST, U.S. Pat. No. 3,528,646, as issued Sept. 15, 1970; MATSON, U.S. Pat. No. 3,822,054, as issued July 2, 1974, and FINK, U.S. Pat. No. 3,870,281, as issued Mar. 11, 1975.
The inventor of this apparatus has also been closely associated with vibration equipment and, in addition to the U.S. Pat. Nos. 3,673,639 and 3,790,137 noted above, by assignment of or application has been instrumental in bringing to the marketplace U.S. Pat. No. 3,112,098 to ANDERSON, as issued Nov. 26, 1963, and his U.S. Pat. No. 3,672,639, as issued June 27, 1972. The above devices, when operated at speeds in excess of five thousand R.P.M.'s, produce noise above one hundred decibels on the A-scale and several produce readings in the one hundred ten to one hundred fifteen levels. The apparatus of this invention produces a noise in the acceptable levels of about eighty dB, and with muffler material to seventy to eighty-two dB (dB readings taken at one meter on A-scale).